COUNTING - PowerPoint PPT Presentation

COUNTING SQL has the ability to count and aggregate values across tuples. However since each SQL expression in the WHERE clause refers to individual tuples, counting usually is the last step. Recall that an SQL expression returns a bag of tuples.

Copyright Complaint Adult Content Flag as Inappropriate

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Download Presentation

PowerPoint Slideshow about 'COUNTING' - bernad

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

A JOIN B, inner join selects tuples that satisfy a join condition, eliminates all tuples that do not satisfy the join condition. A is called the left operand and B is the right operand of the join operation.

A LEFT OUTER JOIN B returns all tuples in the inner join as well as the tuples in A that do not join with any tuples in in B.

A RIGHT OUTER JOIN B returns all tuples in the inner join as well as the tuples in B that do not join with any tuples in in A.

A FULL OUTER JOIN B returns all tuples in the inner join as well as the tuples from A and B that do not participate in the inner join.